Train control



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TTQRNEY Patented July 20, i925.

sereni* ortica.

CHARLES S. BUSHNELL, 0F ROCHESTER, NEVI YORK, ASSIGNOR TO GENERAL AIL-WAY SIGNAL COMPANY, 0F GATES, NEW YORK, CORPORATON OF YRK,

'TRAIN CONTROL.

Application mea october s, 1922. serial no. 593,375.

rllhis invention relates to automatic train speaking, the adjustment orselection to give control systems.

in the practical operation of railway trains, it has 'been found thatthere is a decided difference in the operating characteristics of thetrain control equipment for the' two generalclasses of trains, namely,freightand passenger. The latter class, in mosJ instances, may be'considered to include express and mail trains also. The diference in theoperating characteristics manifests itself in two particulars, in that,(l) lthe speed of freight trains, due to various conditions, isgenerally lower than that'of passenger1 trains, and (2.) that with theuse'of the present standard automatic air-bral re system, vit is muchmore difficult tostop a long freight. train safely under variousconditions, such as, slack between cars, speed, grade, and othertrackway conditions, than it is to stop a passengery train` undersimilarV conditions4 in the ordinaryV operation of railway sysnis, it isoften found desirable orv necesary to use certain engines for pullingpas- ,enf'er trains at times, whereas at other rimes the same enginewill nev used for pulling freight trains. This means that engines forsuch dual service should have train control equipment capable ofadjustment or 'selection to provide the proper speed limits and type ofbrake application snit ole for freight and passenger trains; but it isbelieved that it is not sufficient to merely provide for such adjustmentor selection, because if left solely to the engineer or other employee,a freight train might through carelessness or otherwise be running witha passenger train set-up of speed limits, or perhaps viceversa, althoughthe change from freight to passenger is more likely to be made to taireAadvantage of the higher speed limits.

with the above problems and other con# sidcr ions in mind, Vtheprincipal objects and purposes of the present invention contemplate.thev provision .of means whereby the engineer can. obtain manually theproper set-np or adjustment'of the train control equipment for theparticular vclass ofvtrain, which will not permit him to set up a wrongYcombination. Generally the proper speed limits and kind of automaticbrake application for freight and passenger service is accomplishedautomatically by certain manual manipulations which are necessarily madein changing a locomotive from freight to passenger service and viceversa. More specifically, this comprises the provision of devicesassociati' ed with the signal air pipe usually provided on locomotives,whereby a freight setup.

is made if this signal pipe is not operatively connected with thefollowing train, and whereby a passenger set-up is brought about if thissignal pipe is operatively connected to following oars.

Further objects contemplate the provision of suitable means foreffecting a passenger setfupif an engine-'tender equipment is runningalone, which more specifically consists in the provision of means andmechanisms for effecting a passenger set-up if the usual air-brakepipe-is not operatively connected tocars at either end of theengine-tender equipment, regardless ofthe condition of the signal airpipe.

Other objects, purposes, and characteristic features of this inventionwill appear` as the descripition thereof progresses.

In describing the invention in detail, ref-v erence will be made to theaccompanying drawings, in which Figure l shows a diagrammatic' view ofone embodiment of the invention illustrating in a simple manner how theinvention may be applied to an engine provided with the usual air-signalpipe, certain elements ofthe System being shown in a conventional mannerto illustrate their relation tol the rest of the devices without showingtheir construction in' detail; and

Fig.` 2 shows a modified form of the invention, which has superimposedthereon suitable devicesfor causing a passenger setup when theengine-tender equipment equipped therewith is running alone.

in order to simplify the description of the present invention, it hasbeen shown applied to a very simple type of train control system whichis designed to control either a: passenger or a freight train, each inits own. particularv manner dependent on' cer-v tain adjustments ofparts, and which has the tvvo independent characteristic featuresheretofore mentioned, namely, (1) sets up certain restrictions in themovement of the train, (2) causes a certain kind or degree of brakeapplication upon violation of such restrictions.

Various othertypes of train control de` vices Which set upcertainrestrictions could have been illustrated, such as, arrestrietion set upby a permissive speed cam driven from the wheels of; the vehicle,restrictions in distance that a train is allowedto run in apredetermined interval of time measured by a suitable time controldevice, restrictions in speed controlled by the tloiv of a fiuid from anorifice, and the like. Also various restrictions between the kind or desgree of brake application made When pulling a freight train ascontrasted With a brake application made When pulling a passenger trainmight be illustrated. For instance, a passenger train may have itsbrakes applied automatically7 by venting the brake pipe to what isknovvn as equalization pressure2 Whereas a freight train may beautomatically braked by a lighter brake application, or even by ativo-stage brake application, the first of which is very light andintended for bunching the slack, so to speak, and a second and increasedbrake application for effectively slowing down the train.

lVith these broad principles in mind, the invention has been shown inthe simplest manner by illustrating means for enforcing a single butdiiierent speed limit for freight and for passenger trains, and inillustrating means for causing` a different degree of brake applicationfor these tivo types of trains.

In describing the several embodiments of the invention, it is assumedthat the righthand end of each figure of the drawings is the pilot endof a locomotive and tender and the lefthand end is the tender end ofthis equipment, the tender end being that Which is usually coupled to atrain. The several devices forming elements of the present inventionwill first be separately described, after which the manner in which theyare connected and in Which they cooperate Will be described in detail.

Struczme of Fig. 1.-Tn Figure 1 of the drawings, 1 illustrates the usualair-signal pipe extending from the front end of a locomotive to the rearend of a tender coupled thereto, T 2 being shown from which leads abranch pipe 3 to a source of air supply and a suitable signal (notshown). Near each end of this air-signal pipe 1 is provided a cut-offcock et for cutting ofll air communication between the pipe 3 and theflexible coupling or hose 5 and 6 respectively, the flexible coupling 6being connected to a hose 7 of the first car following the tender,rby asuitable coupling member S. YThe cut-off cocks 4 are each provided witha blade 10,77having a contact sector 11 fastened thereto but insulatedthere` from, which completes an electrical circuit between the contactfingers 12 and 13 when the cut-ofi' cock is in its open position.

Anotherl element of the embodiment of the invention illustratedcomprises a suit` able speed responsive device, ivhich in the presentinstance is of the centrifugal type, later referred to as a governor.'This gow ernor G comprises a shaft- 15 driven from the ivheelsof thevehicle by any suitable means (not shown), having a collar 16 rigidlyfastened thereto, and provided with another collar 17 having aperipheral groove engaging a suitable indicator 18, which is pivoted at19. This collar 1T is slidably mounted on the shaft 15, and is connectedto the collar 1G by links 2() and 21, suitable governor Weights 22 beingprovided at the pivotal connection between these links.

A compression coil spring 23 is provided on the shaft 15 between thecollars 16 and 17, Which urges the governor Weights Q2 toward thisshaft. Fixedly connected to the slidable 'collar 17 is a disk 25 ofinsulating material. Pivotally supported contact meinbers 26 and 27 areprovided which under normal conditions are in contact with stationarycontacts conventionally illustrated by arroivs E28 and 9.9 respectively.It will thus be seen that rotation of the shaft 15 will cause thegovernor Weights 22 to separate, due to centrifugal action, and therebymoving slidable collar 17 toward the collar 16 in opposition to thetension ot' the spring Q3; and that it a predetermined speed has beenexceeded the insulating disk 25 will lift the contact 27 from stationarycontact 25), and that further increase of speed Will cause theinsulating block 30 to lift the movable contact 26 from the stationarycontact 28.

A suitable selecting relay has been provided ivhich may take any one ofa variety of forms, and has been shown conventionally and designated SR.This relay SR is provided with a front contact 31 which is closed whenthis relay is energized, and is provided With a back contact 82 whichcloses a circuit ivhen the relay is deenergized,

A suitable pneumatically operated application valve has been provided,which has been shown in outline only and has been designated A. Thisapplication valve is provided with a pipe connected to the mainreservoir of the usual airbrake system, a pipe 36 for controlling itsoperation by a suitable elcctrically operated device, a pipe 37connected to the usual brake pipe, a pipe 38 connected to an equalizingor capacity reservoir E,

Lacasse and a pipe 39 connected to expansion reservoirs R and R1. lThisapplication valve is constructed tov normally connect the brake pipe tothe equalizing reservoir and connect the reduction reservoirs R and R1to atmosphe're. This normal operated position of the application valve Ais caused by main reser- A von' pressure entering through pipe 35 Whenthe pipe 86 is'closed, the abnormal or operated position of this valvetaking place when the pipe 36 is connected to atmosphere. The functionof this application valve A in its abnormal or operated posit-ion Willbe eX- plained hereinafter in detail in connection Withv the operation.

The flow of pressure fluid through the pipe 36 is controlled by anelectro-pneumatic valve designated E. P. V., which comprises a casing 44having a chamber 40 and having a valve seat in which is adapted to resta valve 41.y The valve 41 is provided With' a valve stem 42 slidablysupported in a top cover 43 of non-magnetic material threaded on thecasing 44. The valve stem 42 is provided with a disk-type armature 45,which in thedeenergized condition of this device is held some distanceabove the coil 4S by a spring 47, whereby energization of this coil 46attractsthe armature and causes the valse 41 to rest ont-he valve seat.

Thek reduction reservoirs R and R1 are connected by a pipe through anelectrically operated reduction valve E. R. V. This reduction valvecomprises a substantially cylnd'rical casing 50, having compartments 51and 52 connected to thevreduction reservoirs R and RI respectively.These compartments 51 and 52 are separated by a partition, having avalve seat in which is adapted to rest a valve 53. The valve 53 isprovided with a stern 54 having an armature 55 connected thereto, thisarmature 55v being lifted away from the non-magnetic cover 56 to urgethe valve 53 againstits seat when the coil 57 is energized.

Operation of Fig. 7.-When the several devices are in the conditionshown, that is, with 'the engine-tender equipment on which they areinstalled having its air-signal pipe 1 operatively connected to cars ateither-'end thereof, a certain restriction uponY the movement of thetrain 'will be enforced which will for convenience be called a passengerset-up in the following description of the operation of the invention.In the embodiment of the invention illustrated in Fig. 1, a movablecontact 27 cooperating with a stationary contact 29 .has beenillustrated in association with the centrifugal speed responsive deviceG in a manner so that these contacts separate 'when a predeterminedspeed has been exceeded. Thisy articular speed may be a maximumrestrictive speed above Which a fre-ight train shall not travel, or maybe a speed that the train shall not exceed under predetermined traiiicconditions ahead, that is, this predetermined speed may be continuallyenforced as maximum speed limit, or it may be a spe-ed limit which isonly enforced during a certain portion of a caution block. f

The other movable contact 26 cooperating with the stationary Contact 28yhas been provided for enforcing a predetermined restrictive speed forpassenger trains under conditions similar to those just referred to forfreight trains. The selecting relay SR has been provided, among otherthings` for shunting the permissive speed contacts 2?.-29 for freighttrain service, so that if. the relay SR is energized the breakingfofconnection between cont-acts 27 and 29 Will not in any tvay adect theelectro-pneumatic valve E. P. V.

Under the proceed' conditions oi the carcarried apparatus illustrated,the electropneumatic valve E. P. V. is energized by a circuit which maybe traced as follows beginning at the battery 60, Wire 61, movableContact 26, stationary contact 28, Wire 62, movable contact 27,stationary contact 29, Wire 63, Winding of the electro-pneumatic valveE. l?. V Wire 64 back tothe battery 60. The energizaton ofthe electro-`pneumatic valve EP. V. closes an opening to the pipe 36, therebymaintaining the application valve A in the brake release position.

Under the conditions of the apparatus as illustrated in the drawings,the selecting relay SR will be. energized through a circuit which may betraced as follows zs-bete-ry 66. VVith this selecting relay SRenergized, it will be noted that its front contact 31 provides ashunting circuit around the contacts 27 and 29, so that only a passengerrestrictive speed limit Will be enforced. f

Let us assume that a train equipped With the apparatus illustrated inFig. 1 is passing along the traclrway and gradually increases its speeduntil the insulating dish 25 lifts the contact 27 from the stationaryContact 29. Nothing particularly will happen at this time, because thesecontacts are shunted -by the contact 31.

Let us assume now that the` speed of the train gradually increases untilthe bloei: of insulation 30 lifts the contacts 26 from the stationarycontact 28. This Will break the circuit through the electro-pneumaticvalve E. P. V., thereby connecting the pipe 36 to atmosphere. This willcause the application valve A to connect pipes 38 and 39 together,thereby allowing the air which is contained in the equalizing reservoirE which is only true when this sign to flow into thereduction reservoirsR and R1 until equalization of pressure takes place. The ratio of volumeof the equalizing reservoir E to that of the sum of the reservoirs R andR1 is such that the desired reduction of pressure below that at whichthe equalizing reservoir pressure was prior to the operation of thevalve A takes' place, that is, the ratio of these reservoirs is suchthat after the valve A has moved to its brake applying position, apressure standard has been set up which bears a certain relation to theinitial brake pipe pressure. The application valve A is furtherconstructed so that when this valve is in its brake applying position,brake pipe pressure from the brake pipe 3T will be allowed to escape toatmosphere until this pressure is the same as the pressure standard setup in the equalizing reservoir E, this being` accomplished in awell-known manner to those skilled in the art of air braking.

It is thus seen that when the air-signal pipe l has one of its eut-oilcocks el ope-n, a, pipe 1s operatively connected to the following cars,that the selecting relay SR will be energized thereby cutting out thelower permissive speed limit intended for freight train purposes only,and will cause the electropneumatic valve E. P. V. to be deenergizedwhen the passenger permissive speed limit has been exceeded; and that anapplication of the brakes occurring under these conditions will cause abrake application corresponding to a reduction of pressure due to theequalization between the equalizing reservoir E and both the reducingreservoirs R and R1, which reduction is greater than would be true ifreservoir E was allowed to equalize with reservoir R only.

Let us assume now that this engine equipment is pulling a freight trainand therefore will not have the signal pipe operatively connected tofollowing cars, it being assumed that freight trains are not providedwith signaling hose. Under this condition, both of the cut-olf cocks atwill be closed and the selecting relay SR will be deenergized forobvious reasons. The deenergization of the selecting relay .SR opens thecontact 3l and causes its back contact 32 to close a circuit through theelectrically operated reducing valve E. R. V., which may be traced asfollows :-starting at the battery 75, wire 7G, back contact 32 of theselecting relay SR, wire 77, winding 57 of the reducing valve E. R. V.,wire 78 back to the battery 75. The energization of this electricallyoperated reducing valve E. R. V. prevents the flow of pressuie fluidbetween reduction reservoirs R and R1. The deenergization of theselecting relay SR now having interrupted the shunt around the contacts27 and 29 will cause a lower permissive speed limit to be enforced, asheretofore explained.

Assuming now that the speed of the vehiele is increased until thecontact 2T is separated from stationary contact 29 by the action of thedisk 25, and causes interruption of the circuit through the E. P. V.,thereby causing operation of the application valve A substantially asdescribed heretofore. it this time, however, when the reservoir E isconnected to the reservoir ll, the fall in pressure, or reduction, isless because the reduction reservoir R1 is now disconnected from thereservoir R. A smaller drop in pressure in the equalizing reservoir Ethrough suitable mechanism in the application valve A causes a smallerreduction in pressure in the brake pipe 3T, and consequently causes acorresponding lighter brake application, as well understood by thoseskilled in the art of air braking.

in arrangement of devices has, therefore, been provided which, when theair-signal pipe is not in use, will enforce a low permissive speed limitin any suitable manner, either under clear, caution, or danger traficconditions; whereby if this permissive speed limit is exceeded a lightbrake application will take place, because the equalizing reservoir E isconnected to a single reduction reservoir R, thereby causing a slightreduction in brake pipe pressure and a corresponding brake application;whereas, it this air-signal pipe l is operatively connected to theair-signal pipe of a following train, a higher permissive speed limitwill be set up which if exceeded will cause a more severe or harderbrake application. This harder brake application taking place becausethe pressure of the equalizing reservoir E will be reduced to a lowerpressure on account of the fact that it at this time will be connectedto two reduction reservoirs R and R1, whereby a heavier brakeapplication will be affected which is considered safe for passengertrain purposes.

In the braking of passenger trains, it is generally considered safe toapply the brakes as hard as the present automatic air brake systempermits without fear of endangering the equipment, or safe stopping ofthe train; whereas a severe and heavy brake application on a freighttrain, especially if it is very long and loaded, is considered dangerouson account of the possibility of buckling the train due to the brakingof the first part of the train before that of the rear end thereof onaccount of the time necessary for the reduced brake pipe pressure totravel to the rear end of such a train.

Modification n Fig. .fi-In Fig. 2 of the drawings has been illustrated amodified form of the present invention in which the (not shown).Nearboth ends of this brake pipe 8l .is provided a cut-off cock 83constructed substantiallythe same as the cut- O cocks l illustrated inFig. 1. These cutoff cocks are provided with an insulated contact sectorSe, which is adapted to close a circuitthrough. the Contact fingers 85andv 86 when this cock is in the closed position.

Y Another clement of the modified form of the invention illustratedcomprises a double check valve D. C. V., which consists of a cylinder87V having a pipe 88 leading from the middle portion thereof, andprovided with cylinder heads 89 and 90 respectively. The cylinder head89 is provided with a pipe 91 connecting to a T 92 in Jthe signal- -pipe1 just ahead the cutoff cock 80, whereas the cylinder head 90 isprovided with a pipe 93 which connects to a T 94 similarly connected. inthe signal pipe on the tender endrthereof. Within the cylinder 87 isslidably contained a piston 96.k Each end of theV piston is providedwith a circular ridge adaptedto engage a packing ring 98 in the end ofthe cylinder.

A. suitable' pneumatically operated switch PS forms another element ofthe-.present in vention, which comprises a cylinder 1.00 provided withan internal flange 101 having a packing ring 102 adjacent thereto, andhaving its one end connected to the pipe 823. Slidabrly contained inthis cylinder is a piston 103', having a piston rod 104e extendingthrough the other' end of the cylinder 100. This piston 103 is normallyurged to the upper position by a compression coil spring 105` containedon the piston. rod 104. To the extreme end of the piston rod 104- isconnected a contact disk 106V by suitable-'ined loting means; This-contactdisk 106, when in its normal position, will electricallyconnect. two stationary contacts conventionally shown as. arrows 1.08.and 109. lt is thus seen. that' if pressure: fluid. is admitted intothe cylinder 100 above the piston 103, that this pistonwi-ll be moved.downward against the tension of the spring' 105, thereby bridge ing' thestationarycontacts 108vand-1109 by the Contact disk 106. l

Let us assume now' that anA engine equipped with .the apparatus.illustrated in Fig. 2 is connectedto a passenger train by thc rear endof its tender, thereby requiring a connection .between the signal hose 6of the tender and the signal hose 7 of the following train, and likewiserequiring a connection between the air-brake hose 110 of the tender andthe air-brake hose 111 of the first following car. Under this condition,both the signal pipe cut-offcoclrand the brake-pipe cut-olf cock on the`tendeiend of the equipe ment will necessarily be opened, whereas thecorrespondingcccks onthe pilot end of the equipment will be in theirclosed position.. Under this the passenger train condition, the presenceof pressure in the signal pipey to the rear Vof the cut-off cock 8O onthe tenderl will. produce a pressure in the pipe 93, thereby forcing`the piston Y96 of. the double check. valve D. C.' V. toward Ythe righi;rthe pipe 91 being opento' tu'zmosphere.Y The piston 96, in moviny to theright, strikes packing ring 98 and forms a tight air seal to prevent anyleakage pastv said n piston to atmosphere. Such movement of pistonL 98also allows pressure fluid to enter the pneumatic switch cylinder 100and move the piston 103 down ward, thereby causing the contact disk. 10Gto bridge statioi'iary contacts 108 land 109. Therbridg-ing of thesecontacts will energize the selecting relay SR, thereby causing apassenger train set-up substantially in the same manner as described inconnectionY with lf the locomotive and tender should hap= pen. to beconnected to a passenger train at its front or pilot end., then valve 8Oat its tender end would be closed, while valve 8O at the other Aendwouldbe y,opened to estabv lish a connection between.Y the air-signal sys temand the signalline of the train. Under these conditions, pistonV v96 ofthe double check valve D. C. V. would be shifted to the other orlefthand position; but pressurewould still be applied to air switch PS,with. the same result described.

Vihen the locomotive equipped as shown in Fig. 2 is coupled to a freighttrain, both cut-ofi' cocks 80 are closed, because there is no signal`pipe or line on a freight train, and these coc rs must be closed t'oprevent escape of air from the signal. pipe. Under these. circumstances,there is no pressure in either pipe 91 or 93, and the air switch PS-opens, deener'gizing selecting relay SR to make the freight trainY speedlimit effective and by energizing coil 57 of valve E.. R. V. disconnectreduction reservoir R1 and. limit theV reduction in brake pipe pressureof an automatic application to that suitable for freight trains.

It should. be noted that the presence of the brake pipe and associatedpartsl have not'performed any function as farV as the operatingconditions thus far described is concerned.- ToY explain functions of.this -llO brake pipe, let us assume now that it is desired to run anengine-tender equipment alone without any following train, and that thisengine-tender equipment is of a high speed typeand therefore able toassume a comparatively high speed safely. Under this condition, all ofthe cut-off cocks and S3 will be closed, because there are nocooperating hose connections to connect to. Under this condition, therewill be no pressure in the cylinder of the pneumatic switch PS and thecontacts 108 and 109 will not be bridged by the Contact disk 106,thereby giving a freight train set-up. On the other hand, however, sinceboth of the cocks 83 are now in their closed position, in order toprevent theY escape of air from the brake pipe, a circuit is completeddue to this condition of thesei cut-oil? cocks.Y

traced as follows z-beginning at the battery 120, wire 121, wire 122,Contact finger 85, contact sector 84:, contact finger 86, wire 123,contact finger 86, contact sector 84, contact finger 85, wires 124 and125, winding of the selecting relay SR, Wire 126 back to the battery120.

This latter circuit performs the same function as doesnthe circuitcontrolled by the double check valve D. C. V., and consequently withthiscircuit closed through the battery 120, the selecting relay SR willvmaintain contact 31 closed and will open contact 32, thus allowing theengine to assume passenger train speed for predetermined trailicconditions ahead; and further energizes the valve E. R. V. to allow amaximum reduction of pressure in the brake pipe in the event ofoperation of the application valve A. An Vengine-tender equipmentrunning alone equipped with Ythe apparatus shown in Fig. 2 may thus berestricted and controlled automatically to the same degree as apassenger train. Y

Having thus shown and described several embodiments ofthe invention asapplied to an exceedingly simple form of train control system, it shouldbe understood that this has been done for the purpose of showing anddescribing an application of the invention in a manner so that it may beeasily understood, and not with a view of showing the particulararrangement preferably employed in practice. It should further beunderstood that various additions, modifications and adaptations of theparticular arrangement'shown may be made, without departing from thescope ofthis invention. For instance, if the permissive speed ofa systememploys the time-distance interval principle. such permissive; speed maybe changed by changing the timing of a suitable time element device;whereas, if a permissive speed cam is used for enforcing speed limits ina caution block, one cam may be This circuitV enerffizes the selectinorrela SR and ma be substituted for another in changing from passenger tofreight, or vice versa, by suitable circuit arrangements. Similarly,other' means may be VVemployed for cutting into service the proper traincontrol apparatus for freight or passenger trains as conditions mayrequire, and in a manner soY tl at it may not be maliciously misused bythe engineer, without departing from the spirit and scope of thisinvention.

lVhat I desire to secure by Letters Patent of the United States, is

1. The method of enforcing different restrictions upon different classesoftrains employing automatic train control apparatus, which consists inproviding the engine pulling such train with suitable apparatus forenforcing restrictions of different character which are respectivelysuitable for a different class of train and which may be adjusted toenforce any one of these restrictions. and in requiring the engineer toadjust said apparatus to enforce the proper restriction for theparticular train his engine is pulling before a proper operativeconnection for the particular train can be made between said engine andtrain.

2. The method of enforcing different restrictions upon differentlclasses of trains and applying the brakes in a manner dependent on thetype of train, which consists in pro-- viding the engine pulling suchtrain with suitable apparatus for enforcingr restrictions of adifferent, character in a diiierent manner, each suitable for adifferent class of train which may be adjusted to enforce any one ofthese restrict-ions, and in requiring` the engineer to adjust saidapparatus to enforce t-he proper restriction for the particular trainhisengine is pulling before a proper operative connection for theparticular tain can be made between said engine and train. Y

3. A device for selecting which of a plurality of train control devicesshall he cffectivecomprising, means made effective for selecting oneparticular train control device when the. usual air-signal line betweenthe engine and train it is pulling in an operative condition.

4. In an automatic train control s vstem, the combinationjvith alocomotive provided with train control apparatus suitable forcontrolling a freight train and with another control apparatus suitablefor controlling a passenger train, of means having its operationdependent on the condition of the air-signaling system between suchlocomotive and the following train for rendering one or the other ofsaid apparatuses effective.

5. In an automatic train control system, the combination with alocomotive provided with train control apparatus suitable forcontrolling a freight train and with anotheil control apparatus suitablefor controlling a passenger train, of means having its operationdependent on the pressure in the airsignal pipe connecting the enginevand the following trainl for rendering one or the other of saidapparatuses eilective.

dln an automatic train control system, the combination with a locomotiveprovided with train cintrol apparatusior en'iorcing speed limitssuitable tor controlling `ieigl'it trains, means enaective'when theusual airsignal pipe is operatively connected to the following trainlier allowing' a higher speed limit, and means eilective when the usualair hralre pipe ot the locomotive is not. operatively connected to othercar tor liiewise peinfiittingA said locomotive to assume higher speedlimits. Y

7. In an automatic train contro-l system, the combination withthe usualengine-tender equipment, of means for establishing restrict-ivespeedlimits suitable for ireight train purposes which if exceeded will causea brake application suitable for such trains, and means eiective iteither the air-signal pipe oi. the equipment is operatively connected toa following train or the brake pipe of this equipment is not operativelyconnected to the other cars for allowing higher rekstrictive speedlimits and :tor making a harder brake application it such speed limitsare exceeded.

8. In a selecting apparatus, the combination of a locomtiveftenderequipment having Dri an air-signal pipeprovided'with a flexibleconnection at each end, a selecting device, a cut-oil. cock adjacenteach flexible comicotion, and means for maintaining said selec tivedevice in one of its operative conditions when there is a predeterminedpressure in said signal pipe, between the cut-oli cock and the flexibleconnection adjacent thereto at either end of the equipment.

9. In a selecting apparatus, the combination Loi a locomotive-tenderequipment pro-v vided with the usual air-signal and brake pipe, eachhaving a flexible. connection at each end thereona selecting device, acut-oli cock. in each of said pipes adjacent each of said flexiblecenections, and means Jfor maintaining said selective device in one ofits operative. conditions when there is a predetermined air pressure. inthe signal pipe between a cut-oli cock and the lleXihle conf nectionadjacent thereto, or when both of the cut-oil' cocks in said brakepipeare closed.

l0; In an automatic train control system, the combination with a railwaytrain comprising the usual locomotive connected to cars and equippedwith the usual air brake and signal equipment including the usual'normally charged brake pipe and a signal pipe, means for automaticallyventing said brake pipe to a predetermined extent when predeterminedspeed limits are exceeded brake pipe to a higher degree when certainspeed limits are exceeded and the signal pipe on the locomotiver isoperatively connected to a signal pipe on cars o said train.

19.. In an automatic train'control system,

the combination with .a railwaytrain comprising the usual locomotiveconnectedl to and signal equipment including the usual normally chargedbrake pipe and a signal pipe, means for automatically venting said brakepipe to a predetermined extent when predetermined speed limits areexceeded, and means for increasing the permissive speed limits and thedegree of venting of the brake pipe if it is automatically vented whenthe signal pipe is operatively con nected to a signal pipe on saidcars..

13. In an automatic train control system, the combination with a railwaytraincomprising the usual locomotive` connected to cars and equippedwith the usualair brake and signal equipment including the usualnormally charged brake pipe and a signal pipe, means for automaticallyventing said brake pipe to a predetermined degree under predeterminedtraino conditi-ons ahead, and means for automatically changing thedegrecv of venting ot saidhr'a-lre pipe under suol-i traiiic conditionsahead it1 said. signal pipe on the locomotive is operative-ly connectedto a. signal pipe on said cars.

lll, In an automaticl train control system, the combination with larailway train comprising the usual locomotive connective to cars. andequipped lwith the usual air lorale and signal equipment including theusual normally charged brake pipe and a signal pipe., means forautomatically venting said hralre pipe to a certain degree underpredetermined traflic conditions ahead, and means for changing thedegree of venting when the brake pipe is automatically vented it thesignal pipe on the locomotive is operatively connected to the sienalpipe on said cars or if the brake pipe on said locomotive is notoperatively connected to a brake pipe of other cars. n

l5. In an automatic train control system, the combination with the usuallocomotivt` tender equipment provided with the Vusual cars and equippedwith the usual air hralre y lill) lll) air brake apparatus, and of meansfor determining whether or not said locomotivetender equipment isconnected to other cars depending on the condition of said air brakeapparatus.

16. In an automatic train control system, the combination with the usuallocomotive provided with the usual brake pipe, and of means fordetermining` whether said brake pipe is operatively connect-ed to othercars comprising, a cut-oli coclr near each end of said brake pipe, andcontacts operatively connected to said cut-oil' cocks.

17. In an automatic train control system the combination with a usuallocomotive provided with the usual signal pipe and of means fordetermining whether said signal pipe is operatively connected to othercars comprising, a cut-oli cock near each end of said signal pipe, andpressure responsive means for determining whether pressure exists insaid signal pipe beyond either of said cut-ottl cocks.

18. In an automatic train control system, the combination with a railwaytrain having a locomotive provided with the usual air brake equipmentincluding the usual brake pipe and signal pipe, and ot' automatic brakeapplying means superimposed thereon comprising, a capacity reservoirnormally comiected to the brake pipe. an expansion reservoir normallyconnected to atmosphere, means connecting the reservoirs together forequalizing the pressures therein and venting the brake pipe to the valueof the equalized pressure when predetermined traffic conditions exist,and means for increasing the volume of said expansion reservoir when thesignal pipe on the locomotive is operatively connected to the signalpipe on the rest oi the train, whereby the degree of brake applicationeffected automatically is higher if the signal pipe is operativelyconnected to the signal pipe of the following train than when it is notso connected.

19. In an automatic train control system, the combination with a railwaytrain having a locomotive provided with the usual air brake equipmentincluding the usual brake pipe having the usual cut-off cocks and asignal pipe which is adapted to be connected to freight cars having onlya brake pipe or to passenger cars having both a brake pipe and a signalpipe, and of automatic brake applying means superimposed thereoncomprising, a capacity reservoir normally connected to the brake pipe,an expansion reservoir normally connected to atmosphere, meansequalizing the pressure of said reservoirs and venting the brake pine tothe value of the equalized pressure when predetermined trafficconditions exist, and means for increasing the volume ot said expansionreservoir when either the signal pipe on the locomotive is operativelyconnected to the signal pipe on the rest of the train or if the brakepipe of the locomotive has both of its cut-olif cocks closed, wherebythe degree of brake application eiected automatically is higher if thelocomotive is operatively connected to a passenger train or is runningalone than when it is operatively connected to a freight train.

20. Apparatus for selecting one of a plurality ot. restrictions in trainmovements in train control apparatus comprising, means for selecting oneparticular restrict-ion in the movements of the train when the usualairsignal line between the engine-tender equipment and the cars of thetrain is in operative condition and for selecting a differentrestriction in the movement of the train when the air-signal line is notin its operative condition.

2l. Apparatus for selecting one of a plurality of restrictions in trainmovements of train control systems comprising. means for selecting oneparticular restriction in the movement of the train when the usual airbrake line between the engine-tender equipment and the other cars (ifany) of the train is in normal operative condition and for selecting adifferent restriction in the movement of the train when the said airbrake line is in its abnormal condition.

22. Apparatus for selecting one of a plurality of restrictions in themovement of a train employing train control apparatus comprising, meansfor selecting one partie` ular restriction in the movement of the trainwhen the usual air-signal line at the rear end of the engine-tenderequipment is connected to the following cars or when the air brake lineat the rear end of the engine-tender equipment is not connected tofollowing cars and for selecting a different restriction in the movementof the train when the air brake line alone is connected to other cars ofthe train.

In testimony whereof, I hereby afiix my signature.

CHARLES S. BUSHNELL.

